This invention relates to systems and methods for processing and collecting blood, blood constituents, or other suspensions of cellular material.
Today people routinely separate whole blood, usually by centrifugation, into its various therapeutic components, such as red blood cells, platelets, and plasma.
Conventional blood processing methods use durable centrifuge equipment in association with single use, sterile processing systems, typically made of plastic. The operator loads the disposable systems upon the centrifuge before processing and removes them afterwards.
Conventional blood centrifuges are of a size that does not permit easy transport between collection sites. Furthermore, loading and unloading operations can sometimes be time consuming and tedious.
In addition, a need exists for further improved systems and methods for collecting blood components in a way that lends itself to use in high volume, on line blood collection environments, where higher yields of critically needed cellular blood components, like plasma, red blood cells, and platelets, can be realized in reasonable short processing times.
The operational and performance demands upon such fluid processing systems become more complex and sophisticated, even as the demand for smaller and more portable systems intensifies. The need therefore exists for automated blood processing controllers that can gather and generate more detailed information and control signals to aid the operator in maximizing processing and separation efficiencies.
The invention provides systems and methods for processing blood and blood constituents that lend themselves to portable, flexible processing platforms equipped with straightforward and accurate control functions.
More particularly, the invention provides a blood separation chamber for rotation about an axis. The chamber includes an interior channel, which includes a recess that extends outside the bounds of the walls establishing separation zone. The recessed interior channel permits the yields of individual blood components separated in the chamber to be maximized without cross-contamination or contamination by other components present in the chamber.
According to one aspect of the invention, the chamber includes inside and outside walls, which extend circumferentially about the axis in a spaced apart relationship to define between them a separation channel. An interior wall extends partially into the separation channel from one of the inside and outside walls toward the other one of the inside and outside walls. The partial interior wall defines a constricted channel along the other wall. The constricted channel includes a recess extending into the other wall. A first passage communicates with the separation channel one side of the recess. A second passage communicates with the separation channel on the other side of the recess.
One of the first and second passages can be configured to convey blood into the separation channel through the recess. Alternatively, one of the first and second passages can be configured to convey blood from the separation channel through the recess.
In one embodiment, the partial interior wall extends from the inside wall toward the outside wall. In this arrangement, the recess is in the outside wall and is radially spaced from the rotational axis farther than adjacent regions of the outside wall. Red blood cells can exit the separation channel through the recess. Because the recess extends beyond the outside (i.e., high-g) wall, the interface between the red blood cells and the buffy coat can be positioned very close to the high-g wall during blood processing, without spilling the contents of the buffy coat (e.g., leukocytes or platelets) into the red blood cell collection passage. The recessed exit thereby permits red blood cell yields to be maximized (in a red blood cell collection procedure) or an essentially platelet-free plasma to be collected (in a plasma collection procedure).
In one embodiment, the blood separation chamber includes a second partial interior wall extending partially into the separation channel from one of the inside and outside walls toward the other one of the inside and outside walls, to thereby define a second constricted channel along the other wall. In this arrangement, the second constricted channel can also include a second recess extending into the other wall. A third passage can communicate with the separation channel on one side of the second recess.
In one embodiment, the inside and outside walls, the partial interior wall or walls, and recess or recesses comprise a unitary formed body.
Other features and advantages of the inventions are set forth in the following specification and attached drawings.